Question

In the following exercises, evaluate each expression.

$9a-2b-8$when $a=-6$ and$b=-3$

Short answer

The value obtained is $-56$.

Step-by-step solution

Step 1. Given Information:

The given expression is $9a-2b-8$and the value of the variables are $a=-6$and $b=-3$.

Step 2. Substitute the values:

Substitute $-6$for $a$and $-3$for $b$into the given expression $9a-2b-8$.

$9\left(-6\right)-2\left(-3\right)-8$

Step 3. Multiply:

Perform multiplication from left to right in the obtained expression. Use the fact that the product of two negative numbers is again a negative number.

$\left(-54\right)-\left(-6\right)-8$

Step 4. Subtract:

Subtract $-6$from $-54$in the obtained expression.

$\begin{array}{rcl}-54-\left(-6\right)-8& =& -54+6-8\\ & =& -48-8\end{array}$

Step 5. Subtract:

Subtract 8 from $-48$in the obtained expression.

$-48-8=-56$

Step 6. Conclusion:

The value obtained is $-56$.